A Review of the GIS Very Fast Transient Overvoltage Characteristics Study

The breaking and closing operations of disconnect switches in GIS can generate steep wave front, high amplitude, high frequency very fast transient overvoltage (VFTO), which can cause hazards to the internal electrical equipment and external connected equipment of GIS. This paper outlines the generation mechanism and characteristics of GIS VFTO, the simulation modelling of VFTO, the design of the test circuit, and the factors affecting the characteristics of VFTO, which are of practical value for the stable operation of GIS equipment under severe cold and humid conditions.